Treating hydrocarbon distillates



3,097,158 TREATiNG HYDRGQAREEN DHSTILLATES William K. T. Gieim, islandLake, I'll, assignor to Universal Gil Products Company, Des Plaines,111., a corporation of Delaware No Drawing. Filed Sept. 12, 1962, Ser.No. 223,260 6 tllairns. (Cl. Mid-204) This invention relates to thetreatment of sour hydrocarbon distillates in order to produce adistillate of reduced mercaptan content and of acceptable color.

Sour hydrocarbon distiliates are subjected to sweetening in order toreduce the mercaptan content of the distillate. In the sweeteningreaction, the mercaptans are oxidized to disulfides. The disulfides aresoluble in the hydrocarbon distillate and remain in the distillate.However, when certain kei osenes are subjected to sweentening, the colorof the kerosene depreciates. This is objectionable because consumersprefer a good color kerosene and difficulty is encountered in marketingthe off-color kerosene. The present invention provides a novel processfor improving the color of the kerosene after sweetening.

The exact mechanism which causes discoloration of the hydrocarbondistillate during sweetening has not been elucidated. Apparently some ofthe constituents of the hydrocarbon distillate undergo reaction to formcolor bodies. For example, it is believed that polyalkylphenolscontained in the hydrocarbon distillate are oxidized to quinones andthat the quinones cause discoloration of the hydrocarbon distillate.Accordingly, in order to improve the color of the hydrocarbon distillateafter sweetening, it is important to act upon these color bodies but notto adversely affect the other constituents of the other hydrocarbondistillate. It is a particular advantage of the novel process of thepresent invention that the further treatment of the sweetened keroseneapparently reacts with the color bodies but does not react with theother constituents. 'For example, the disulfides entrained in thesweetened kerosene should not be converted back to merca-ptans. As willbe shown in an example, appended to the present specifications,treatment of the sweetened kerosene in the manner herein set forthcaused substantially no increase in the mercaptan content of the finallytreated kerosenes.

. In one embodiment the present invention relates to a combinationprocess for treating sour hydrocarbon distillate to produce a distillateof reduced mercaptan content and of acceptable color, which comprisesoxidizing Inercaptans contained in said distillate to disulfides andthereafter treating the distill-ate with a hydrocarbon soluble acylhydrazide.

In a specific embodiment the present invention relates to a process fortreating sour kerosene which comprises reacting said mercaptanscontained in said kerosene with air in the presence of a phthalocyaninecatalyst and thereafter treating said kerosene with p-toluene sulfonylhydrazide.

The novel process of the present invention is used for the treatment ofany hydrocarbon fraction. While the process may be usedfor the treatmentof norm-ally gaseous hydrocarbons, gasoline, naphtha, etc., it isparticularly useful for the treatment of hydrocarbon distillates heavierthan gasoline, including kerosene, jet fuel, solvent, stove oil,rangeoil, burner oil, gas oil, fuel oil, etc. In general, the kerosenewill have an initial boiling point of from about 300 to about 450 F. andan end boiling point of from about 475 to about 550 F. Solvents andstove oil, for example, usually have initial boiling points within therange of from about 350 to about 500 F. and end boiling points of fromabout 525 to about 600 F.

Any suitable sweetening process may be employed. One process comprisesthe conventional doctor sweet- 3,097,158 Patented July 9, 1963 eningprocess in which the hydrocarbon distillate is treated with doctorsolution (sodium plumbite) and sulfur to oxidize the mercaptans todisulfides. Another conventional process is the copper treating processin which the mercapt-ans are reacted with copper chloride, either as aslurry or as a fixed bed, to oxidize the mercaptans to disulfides. Othersweetening processes include the Hypochlorite process, and variousmodifications of the processes set forth above.

Another process tor oxidizing mercapt-ans to disulfides utilizes aphthalocyanine catalyst. Any suitable pht-halocyanine catalyst may beused and preferably comprises a metal phthalocyanine. Particularlypreferred rnetal phthalocyanines include cobalt phthalocyanine andvanadium phthalocyanine. Other metal phth-alocyanines include ironphthalocyanine, copper phthalocyanine, nickel phthalocyanine, chromiumphthalocyanine, etc. The metal phthalocyanine, in general, is notreadily soluble in aqueous solvents and, therefore, when used in anaqueous alkaline solution or for ease of compositing with .a solidcarrier, a derivative of the phthalocyanine is preferred. A particularlypreferred derivative is the sulfonated derivative. Thus, an especiallypreferred phthalocyanine catalyst is cobalt phthalocyanine sulfonate.Such a catalyst comprises cobalt phthalocyanine disulfonate and alsocontains cobalt phthalocyanine monosulfonate. Another preferred catalystcomprises vanadium phthalocyanine sulfonate. These compounds may beobtained from any source or prepared in any suitable manner as, forexample, by reacting cobalt or vanadium phthalocyanine with 2550% fumingsulfuric acid. While the sulfonic acid derivatives are preferred, it isunderstood that other suitable derivatives may be employed. Otherderivatives include particularly the carboxylated derivative which maybe prepared, for example, by the action of trichloroacetic acid on themetal phthalocyanine or by the action of phosgene and aluminum chloride.In the latter reaction the acid chloride is formed and may be convertedto the desired carboxylated derivative by conventional hydrolysis.

Treatment of the hydrocarbon distillate in the presence of thephthalocyanine catalyst preferably is effected in the presence of analkaline reagent. Any suitable alka- 'line reagent may be employed. Apreferred reagent comprises an aqueous solution of an alkali metalhydroxide such as sodium hydroxide (caustic), potassium hydroxide, etc.Other alkaline solutions include aqueous solutions of lithium hydroxide,rubidium hydroxide, cesium hydroxide, etc. although, in general, thesehydroxides are more expensive and, therefore, generally are notpreferred for commercial use. Preferred alkaline solutions are aqueoussolutions of from about 1% to about 50% and more preferably 5% to 25% byweight concentration of sodium hydroxide or potassium hydroxide. Whilewater is the preferred solvent, it is understood that other suitablesolvents may be used including, for example, an aqueous solution ofalcohol, ketone, etc.

When using the phthalocyanine catalyst, air, oxygen or other suitableoxidizing agent is introduced into the reaction zone. In some cases, thehydrocarbon distillate may contain entrained air in a sufficient amountto effect the desired oxidation, but usually it is desirable tointroduce extraneous air in order to be sure that sufiicient air ispresent for the desired purpose.

Treating of the hydrocarbon distillate with the phthalocyanine catalystis eifected at any suitable temperature,-

Which may range from ambient to 210 F. when operating at atmosphericpressure, or up to about 400 F. or more when operating atsuperatmospheric pressure. In general, it is preferred to utilize aslightly elevated temperature which may range from about F. to about F.Atmospheric pressure or super-atmospheric about 500 parts per million byweight of the alkaline reagent solution. In one embodiment the catalystpreviously is prepared as a solution in a suitable solvent includingammoniated water, aqueous sodium hydroxide, etc., and then is introducedin this manner to the oxidat-ion zone. In another embodiment thecatalyst is added as such to the oxidation zone, to become dissolved inthe alkaline reagent solution therein.

When the catalyst is employed as a fixed bed in the oxidation zone, thecatalyst is prepared as a composite with a solid support. Any suitablesupport may be employed and preferably comprises activated charcoal,coke or other suitable forms of carbon. In some cases the support maycomprise silica, alumina, magnesia, etc. or mixtures thereof. The solidcatalyst is prepared in any suitable manner. In one method, preformedparticles of the solid support are soaked in a solution containing thecatalyst, after which excess solution is drained off and the catalyst isused as such or is subjected to a drying treatment, mild heating,blowing with air, hydrogen, nitrogen, etc., or successive treatmentsusing two or more of these treatments prior to use. In other methods ofpreparing the solid composite, a solution of the phthalocyanine catalystmay be sprayed or poured over the particles of the solid support, orsuch particles may be dipped, suspended, immersed or otherwise contactedwith the catalyst solution. The concentration of phthalocyanine catalystin the composite may range from 0.1% to by weight or more of thecomposite.

In a batch type operation, the sour hydrocarbon distillate, alkalinereagent solution and catalyst are disposed in a reaction zone, and airis bubbled therethrough until the desired oxidation is completed. In acontinuous type operation, the sour hydrocarbon distillate, alkalinereagent solution land catalyst, when the latter is employed in dissolvedform, are supplied to the oxidation zone, preferably at a lower portionthereof. It is understood that the catalyst and alkaline reagentsolution may be introduced to the reaction zone either separately or inadmixture and either commingled with or separate from the sourhydrocarbon distillate. In a fixed bed continuous process, the catalystis disposed as a fixed bed in a reaction zone, and the sour hydrocarbondistillate, air and alkaline solution, when desired, are passed into thereaction zone, in upward or downward flow, and either together orseparately.

Regardless of the particular operation employed, the products areseparated to recover treated hydrocarbon distillate of reduced mercaptancontent and to separate alkaline reagent solution for reuse in theprocess. When the soluble catalyst is employed, the catalyst isrecovered in admixture with the alkaline reagent solution and isrecycled therewith for further use in the process. When desired,additional quantities of phthalocyanine catalyst may be addedcontinuously or intermittently during the treatment of the sourhydrocarbon distillate.

As hereinbefore set forth, the hydrocarbon distillate, following thetreatment with phthalocyanine catalyst, in many cases, will be of poorcolor. As will be shown in an example appended to the presentspecifications, such treatment of kerosene having an initial Sayboltcolor of 30 resulted in a treated kerosene having a Saybolt color ofabout 0. In accordance with the present invention, the kerosene now istreated with a hydrocarbon soluble acyl hydrazide.

Any suitable hydrocarbon soluble acyl hydrazide is used in accordancewith the present invention. The acyl hydrazide is illustrated by thefollowing general formula:

1 t t RXNNH where Risa hydrocarbon radical, n is an integer of from 1 to2, and X is selected from the group consisting of sulfur and carbon. Rin the above general formula preferably is selected from aliphatic,aryl, aliphatic aryl, aryl aliphatic and cycloaliphatic groups. The acylhydrazide is hydrocarbon soluble and, therefore, R contains at least 4and preferably at least 6 and up to 3G or more carbon atoms.illustrative examples of different R groups will be set forthhereinafter.

Where X in the above general formula is sulfur, a particularly preferredacyl hydrazide is p-toluene sulfonyl hydrazide (also named p-toluenesulfonyl hydrazine). p-Toluene sulfonyl hydrazide is availablecommercially or it may be prepared in any suitable manner. One method ofpreparing p-toluene sulfonyl hydrazide is by the reaction of toluenewith chlorosulfonic acid to form p-toluene sulfonyl chloride and thenreacting the patoluene sulfonyl chloride with hydrazine.

Other aromatic sulfonyl hydrazides include benzene sulfonyl hydrazide,xylene sulfonyl hydrazide, ethylbenzene sulfonyl hydrazide,diethylbenzene sulfonyl hydrazide, propylbenzene sulfonyl hydrazide,dipropylbenzene sulfonyl hydrazide, butylbenzene sulfonyl hydrazide,dibutylbenzene sulfonyl hydrazide, pentylbenzene sulfonyl hydrazide,dientylbenzene sulfonyl hydnazide, hexylbenzene sulfonyl hydrazide,dihexylbenzene sulfonyl hydra zide, heptylbenzene sulfonyl hydrazide,diheptylbenzene sulfonyl hydrazide, octylbenzene sulfonyl hydrazide,dioctylbenzene sulfonyl hydrazide, nonylbenzene sulfonyl hydrazide,dinonylbenzene sulfonyl hydrazide, decylbenzene sulfonyl hydrazide,didecylbenzene sulfonyl hydrazide, undecylbenzene sulfonyl hydrazide,dodecylbenzene sulfonyl hydrazide, tridecylbenzene sulfonyl hydrazide,tetradecylbenzene sulfonyl hydrazide, pentadecylbenzene sulfonylhydrazide, hexadecylbenzene sulfonyl hydrazide, heptadecylbenzenesulfonyl hydrazide, octadecylbenzene sulfonyl hydrazide,nonadecylbenzene sulfonyl hydrazide, eicosylbenzene sulfonyl hydnazide,etc., and correspondingly substituted naphthalene sulfonyl hydrazides,anthracene sulfonyl hydrazides, etc. The alkaryl sulfonyl hydrazidescontain alkyl groups which preferably have from 1 to about 20 carbonatoms and include the specific compounds hereinbefore set forth. Thealkyl group preferably is in a position para to the sulfonyl group.

Illustrative examples of hydrocarbon sodium aralkyl sulfonyl hydrazidesinclude benzyl sulfonyl hydrazide, phenylethyl sulfonyl hydrazide,phenylpropyl sulfonyl hydrazide, phenylbutyl sulfonyl hydrazide,phenylpentyl sulfonyl hydrazide, phenylhexyl sulfonyl hydrazide, etc.Cycloalkyl sulfonyl hydnazides include cyclopentyl sulfonyl hydrazide,cyclohexyl sulfonyl hydrazide, etc. and corresponding alkylcycloalkylsulfonyl hydrazides.

Where X in the above general formula is sulfur and R is an aliphaticradical, illustrative compounds include butyl sulfonyl hydrazide, amylsulfonyl hy-drazides, hexyl sulfonyl hydrazide, heptyl sulfonylhydrazide, octyl sulfonyl hydrazide, nonyl sulfonyl hydrazide, decylsulfonyl hydrazide, undecyl sulfonyl hydrazide, dodecyl sulfonylhydrazide, tridecyl sulfonyl hydrazide, tetradecyl sulfonyl hydrazide,pentadecyl sulfonyl hydrazide, hexadecyl sulfonyl hydrazide, etc. asillustrative of the saturated derivatives, and butenyl sulfonylhydrazide, pentenyl sulfonyl hydrazide, hexenyl sulfonyl hydrazide,heptenyl sulfonyl hydrazide, octenyl sulfonyl hydrazide, nonenylsulfonyl hydrazide, decenyl sulfonyl hydrazide, undecenyl sulfonylhydrazide dodecenyl sulfonyl hydrazide, tridecenyl sulfonyl hydrazide,tct-radecenyl sulfonyl hydrazide, pentadecenyl sulfonyl hydrazide,hexadecenyl sulfonyl hydrazide, heptadecenyl sulfonyl hydrazide, oc-

tadecenyl sulfonyl hydrazide, nonadecenyl sulfonyl hydraz'ide, eicosenylsulfonyl hydrazide, etc. as illustrative of the unsaturated derivatives.

Where X in the above general formula is carbon, illustrative acylhydrazides include butyryl hydrazide, valeryl hydrazide, caproylhydrazide, eaprylyl hydrazide, capryl hydrazide, lauryl hydrazide,myristyl hydrazide, palmityl hydrazide, stearyl hydrazide, arachidylhydrazide, behenyl hydrazide, lign-oceryl hydrazide, ceroty l hydrazide,etc. as illustrative of those derived from saturated fatty acids, anddecylenyl hydrazide, stillingyl hydraz-ide, dodecylinyl hydraxide,palmiloleyl hydraxide, oleyl hydrazide, ricin-oleyl hydrazide,petrocelinyl hydrazide, vaccenyl hydrazide, linoleyl hydrazide,eleostearyl hydrazide, licanyl hydrazide, parinaryl hydrazide, gadoleylhydrazide, arachidonyl hydrazi'de, cetoleyl hydrazide, erucyl hydrazide,selacholeyl hydrazide, etc. as illustrative of those derived fromunsaturated fatty acids. The fatty acid hydrazides are prepared in anysuitable manner as, for example, by the reaction of a fatty acid esterwith hydrazine. Thus, valeryl hydrazide is prepared by the reaction ofmethyl valer-ate or ethyl valerate with hydrazine. In another method,the acyl hydrazi-de is prepared by the reaction of the aliphatic acidchloride with hydrazine.

Illustrative examples of other acid hydrazides include bcnzoylhydrazide, toluyl hydnazide, salicyoyl hydrazide, anisoyl hydrazide,etc., naphthoyl hydrazide, cyclopentyl formyl hydrazide, cyclopentylacetyl hydrazide, cyclopenty'l propionyl hydrazide, cyclopentyl butyrylhydrazide, etc., cyclohexyl formyl hydrazide, cyclohexyl acetylhydrazide, cyclohexyl propionyl hydrazide, cyclohexyl butyryl hydrazide,etc.

From the above description, it will be seen that a number of differentacyl hydrazides may be used in accordance with the present invention.However, it is understood that all of the acyl hydrazides are notnecessarily of equivalent activity in improving the color of thehydrocarbon distillate.

Treatment of the hydrocarbon distillate with the acyl hydrazide iseffected in .any suitable manner. In a preferred embodiment, thetreatment is effected in the presence of an alkaline reagent whichconveniently is an aqueous solution of an alkali metal hydroxide. Thealkali metal hydroxide is selected from those hereinbefore specificallyset forth in connection with the oxidation of the hydrocarbon distillatein the presence of the phthalocyanine catalyst. In another embodimentthe alkaline reagent may comprise ammonium hydroxide, alkylamines, etc.

In one embodiment treatment of the hydrocarbon distillate with the acylhydrazide is effected in a batch type operation. In this method thehydrocarbon distillate, alkali metal hydroxide solution and acylhydrazide are supplied to a reaction vessel equipped with mixing bladesor other suitable stirring mechanism to provide intimate mixing of thereactants. In a continuous type operation the hydrocarbon distillate ispassed, either countercurrently or concurrently, into contact with theacyl hydrazide and alkali metal hydroxide, when employed, in a suitablevessel. The vessel preferably is provided with suitable contacting meansincluding side to side pans, bubble decks, bubble trays, perforatedplates, etc. and/ or a fixed bed of inert packing material. Followingthe contacting, the reaction mixture is processed to recover thesweetened hydrocarbon distillate of improved color. When an aqueoussolution of alkaline reagent is employed, the reaction mixture isallowed to separate into a hydrocarbon phase and an aqueous phase ineither the zone of contacting or in a different zone, and each phase isseparately withdrawn. Following separation and removal of thehydrocarbon distillate, the hydrocarbon distillate preferably is waterwashed in order to remove alkaline solution and other water solublematerials from the hydrocarbon distillate.

The treatment of the hydrocarbon distillate with the acyl hydrazidepreferably is effected at a mild temperature which may range fromambient and generally will not exceed about 200 F. The pressure willvary with the particular type of operation and may range fromatmospheric to 1000 pounds or more, generally being in the range fromatmospheric to about 200 pounds per square inch.

For economic reasons it is preferred to use the acyl hydrazide in assmall a concentration as satisfactory for the purpose. Because it isbelieved that the acyl hydrazide decomposes during use, provision shouldbe made in a continuous type process for the addition of acyl hydrazideas required, said addition being intermittently or continuously. Theconcentration of acyl hydrazide generally will be within the range offrom about 0.0001% to about 1% by weight of the hydrocarbon distill-ate.

While the combination process of the present invention is particularlyapplicable to the treatment of sour hydrocarbon distillates, it isunderstood that it may be used for the treatment of mercaptan-containingfractions from other sources as, for example, alcohols. =In stillanother application, the novel features of the present invention areemployed for the oxidation of mercaptans synthetically prepared orrecovered as a special fraction containing the mercaptan as asubstantial or major portion thereof. In such cases, the mercaptan isoxidized to the corresponding disulfide and color depreciation isminimized.

The following examples are introduced to illustrate further the noveltyand utility of the present invention but not with the intention ofunduly limiting the same.

Example I A commercial kerosene having an initial boiling point of 370F., ,an end boiling point of 520 F., a mercaptan content of 0.239% byweight and a Saybolt color of 30 was treated at 122 F. with air and anequal volume of an aqueous 10 Baum sodium hydroxide solution containing250 parts per million of cobalt phthalocyanine disulfonate catalyst. Thetreatment was efiected in a batch type operation for 60 minutes.

The treated kerosene was separately recovered and now had a mercaptansulfur content of 0.0004% by weight, but the Saybolt color of thekerosene had depreciated to about 0.

500 g. of the kerosene treated in the above manner were mixed with 50 g.of 10% sodium hydroxide solution and 0.1 g. of p-toluene sulfonylhydrazide and stirred for one hour at an average temperature of about158 F. Following the reaction, the mixture was allowed to settle into anupper kerosene phase and a lower aqueous caustic phase. The kerosene wasseparately removed and was washed three times with 200 mls. of water.The kero sene now had a Saybolt color of 14 and a mercaptan content of0.0005 by weight.

From the above data, it will be seen that the treatment of the kerosenewith the acid hydrazide improved the Saybolt color from 0 to '14 and hadno substantial effect on the mercaptan content. As hereinbefore setforth, it is important that this treatment does not convert thedisulfides contained in the kerosene back to mercaptans.

Example II An aromatic solvent having an initial boiling point of 360 F.and an end boiling point of 580 F. is treated with air in the presenceof vanadium phthal-ocyanine sulfonate catalyst at F. and 50 pounds persquare inch pressure in a batch type operation. The sweetened butdiscolored solvent oil then is treated at F. with stearyl hydrazine in abatch type operation. The stearyl hydrazide is used in a concentrationof 0.2% by weight of the solvent oil. The treating is effected in thepresence of 20 Baum potassium hydroxide solution in a concentration of5% by weight of the solvent oil. After the treating is completed, thesolvent is separated as an upper layer from a lower aqueous potassiumhydroxide layer.

The solvent then is washed with water to remove any entrained potassiumhydroxide and other Water-soluble materials. The finally treated solventis reduced in mercaptan content and is of acceptable color.

Example III A sour West Texas kerosene having a mercaptan sulfur contentof 0.15% by weight is subjected to sweetening at 110 F. and 75 poundsper square inch pressure in contact with air and cobalt phthalocyaninesulfonate catalyst. The kerosene, in admixture with an aqueous Baumcaustic solution and air, is passed upwardly through a zone containingthe phthalocyanine catalyst as a fixed bed in a reaction zone, and theefiluent products are passed into a settling zone Where excess air isvented. The kerosene separates from the sodium hydroxide solution and isseparately withdrawn from the process. The kerosene now has a mercaptansulfur content of about 0.002% by Weight but is oif-color. The kerosenethen is treated with benzyl sulfonyl hydrazide, used in a concentrationof 0.05% by weight of the kerosene, at a temperature of 140 F. in thepresence of 5 Baum sodium hydroxide solution. The kerosene is washed toremove entrained sodium hydroxide and other water-soluble materials. Thefinally treated kerosene is reduced in mercaptans and is of acceptablecolor.

Example IV Sour jet fuel is sweetened in a conventional doctor treatingprocess in which the jet fuel is mixed with fresh sodium plumbitesolution at ambient temperature, after which free sulfur is added andthe mixing is continued. The reaction mixture then is allowed to settleand the doctor solution is separated from the treated jet fuel. The jetfuel, now reduced in mercaptans, is mixed with valeryl hydrazide and 5Baum potassium hydroxide solution. The mixture is stirred at 135 F. for45 minutes and then is allowed to settle into an upper jet fuel phaseand a lower aqueous phase. Each phase is separately withdrawn and thejet fuel then is water washed to remove entrained caustic and otherwater-soluble materials. The jet fuel now is of reduced mercaptancontent and of acceptable color.

I claim as my invention:

1. A combination process for treating a sour hydroa carbon fraction toproduce a product of reduced mercaptan content and of acceptable color,which comprises oxidizing mercaptans contained in said fraction todisulfides and thereafter treating said fraction with a hydrocarbonsoluble acyl hydrazide.

2. A combination process for treating sour hydrocarbon distillate toproduce a distillate of reduced mercaptan content and of acceptablecolor, which comprises oxidizing mercaptans contained in said distillateto disulfides and thereafter treating the distillate with a hydrocarbonsoluble aromatic sulfonyl hydrazide.

3. A combination process for treating sour hydrocarhon distillate toproduce a distillate of reduced mercaptan content and of acceptablecolor, which comprises oxidizing mercaptans contained in said distillateto disulfides and thereafter treating the distillate with a hydrocarbonsoluble aliphatic sulfonyl hydrazide.

4. A combination process. for treating sour hydrocarbon distillate toproduce a distillate of reduced mercaptan content and of acceptablecolor, which comprises reacting mercaptans contained in said distillatewith an oxidizing agent in the presence of a phthalocyanne catalyst toform disulfides and thereafter treating the distillate'with ahydrocarbon soluble acyl hydrazide.

5. A combination process for treating sour kerosene to produce akerosene of reduced mercaptang content and of acceptable color, whichcomprises reacting mercaptans contained in said kerosene with air in thepresence of cobalt phthalocyanine sulfonate catalyst and alkalinesolution to oxidize said mercaptans to disulfides, separatng treatedkerosene, thereafter further treating the kerosene with p-toluenesulfonyl hydrazide and alkaline solution, and Water washing the thustreated kerosene.

6. A combination process for treating sour kerosene to produce akerosene of reduced mercaptan content and of acceptable color, whichcomprises reacting mercaptans contained in said kerosene with air in thepresence of vanadium phthalocyanine sulfonate catalyst and alkalinesolution to oxidize said mercaptans to disulfides, separating treatedkerosene, thereafter further treating the kerosene with p-toluenesulfonyl hydrazide and alkaline solution, and water washing the thustreated kerosene.

No references cited.

1. A COMBINATION PROCESS FOR TREATING A SOUR HYDROCARBON FRACTION TOPRODUCE A PRODUCT OF REDUCED MERCAPTAN CONTENT AND OF ACCEPTABLE COLOR,WHICH COMPRISES OXIDIZING MERCAPTANS CONTAINED IN SAID FRACTION TODISULFIDES AND THEREAFTER TREATING SAID FRACTION WITH A HYDROCARBONSOLUBLE ACYL HYDRAZIDE.
 2. A COMBINATION PROCESS FOR TREATING SOURHYDROCARBON DISTILLATE TO PRODUCE A DISTILLATE OF REDUCED MERCAPTANCONTENT AND OF ACCEPTABLE COLOR, WHICH COMPRISES OXIDIZING MERCAPTANSCONTAINED IN SAID DISTILLATE TO DISULFIDES AND THEREAFTER TREATING THEDISTILLATE WITH A HYDROCARBON SOLUBLE AROMATIC SULFONYL HYDRAZIDE.
 3. ACOMBINATION PROCESS FOR TREATING SOUR HYDROCARBON DISTILLATE TO PRODUCEA DISTILLATE OF REDUCE MERCAPTAN CONTENT AND OF ACCEPTABLE COLOR, WHICHCOMPRISES OXIDIZING MERCAPTANS CONTAINED IN SAID DISTILLATE TODISULFIDES AND THEREAFTER TREATING THE DISTILLATE WITH A HYDROCARBONSOLUBLE ALIPHATIC SULFONYL HYDRAZIDE.